[Human Guide] Add 'What %raw becomes' decision-tree section #54

Proposal

ReScript's %raw (and TS's unsafe!/as any) is a debt marker, not a feature. The migration guide should give a decision tree:

1. Is there a typed binding (affinescript-dom, affinescript-pixijs, etc.)? Use it.
2. Is the binding missing? Add it to the relevant binding package; do NOT inline %raw equivalent.
3. Is the operation fundamentally untyped? Use a documented Unsafe.embed escape with a comment naming why.

Source observation

Main.res has %raw blocks for: console.log (replaceable: typed Console), error rendering (replaceable: typed DOM binding), exception introspection (replaceable: structured Result + sum). All three were translated cleanly in migration/main/.

Companion

This pairs with a separate repo-level RFC on affinescript-{dom,pixijs} production-readiness — the typed bindings need to exist for this decision tree to recommend option 1.

Filed from idaptik Wave 3 pilot. See LESSONS.md and PILOT.md. Idaptik commit hyperpolymath/idaptik@aef38db.